Callas was known for his rubbery face, trademark nervous chattering, and dark comedy. His first television appearance was in 1963 on The Hollywood Palace, and he soon was opening for Frank Sinatra in nightclubs around the country. In 1965 he played Lefty in a gambling parlor/laundry in The Munsters, season 2, episode 16, "Herman Picks a Winner." He made nearly 50 appearances on The Tonight Show Starring Johnny Carson. Appearing on an episode of The Merv Griffin Show in 1965, one of the guests, Jerry Lewis, practically fell off his chair in hysterics as Callas performed his hunting routine. Lewis turned to Griffin and said he had to use Callas in his current project. That one appearance on the Griffin show landed Callas a role in the 1967 Lewis film The Big Mouth. Lewis recalled the story on his short-lived 1984 talk show, in which Callas served as his sidekick and performed the hunting routine.[3]

He was a regular guest on the Dean Martin Show roasts where he was called on to poke fun at celebrities, including Frank Sinatra[4] and Don Rickles,.[5] He also appeared on The Andy Williams Show at various times as "Captain Weird", a parody of superheroes. Callas's only known dramatic role was that of a restaurant owner, Malcolm Argos, in the 1970s show, Switch. He was also a regular performer on The ABC Comedy Hour in 1972.[3] He was a semiregular on The Flip Wilson Show and co-host of The Joey Bishop Show. His last television appearances were on Larry The Cable Guy's Christmas Spectacular (2007) and Larry The Cable Guy's Star-Studded Christmas Extravaganza (2008).[1]

On January 27, 2011, Callas died of natural causes at age 83, in his home in Las Vegas, Nevada. He is survived by his sons, Mark and Larry. His wife, Evelyn, died six months earlier, age 88.

Tony Belmont, executive director of the National Comedy Hall of Fame in St. Petersburg, Florida, said of Callas upon his death: "There were two things he did that made his career. He could think very fast on his feet, and he had an unbelievable number of sounds that he made with his voice. He would tell a joke about two guys hunting. If you or I told it, the joke wasn't so funny. But Charlie made it hysterical by sticking in these sounds; so you would hear the gun cocking, the duck flying overhead, the explosion of the shotgun and then the duck falling and screaming all the way to the ground."[6]